1. Field of the Invention
The invention relates to a harmony effect imparting apparatus and a karaoke amplifier which are used in a karaoke system.
2. Related Art
In a karaoke system, a singing voice (hereinafter, referred to as a vocal sound) which is picked up by a microphone, and a reproduced signal of a music source such as melody and accompaniment sound are mixed with each other by a karaoke amplifier, and then output as a sound from a loudspeaker. Generally, such a karaoke amplifier is provided with a circuit which imparts an echo or reverb to the vocal sound signal input through the microphone, as means for enhancing the stage effect of the singing.
Recently, in addition to such impartation of an echo or reverb, a further special stage effect is requested. In order to comply with such a requirement, various kinds of karaoke vocal adaptors which impart several sound effects to a vocal sound signal have been proposed. When the owner or user inserts such a karaoke vocal adaptor between a microphone and a karaoke amplifier, a desired sound effect can be imparted to a vocal sound produced from a loudspeaker, thereby enhancing the stage effect.
Some of the proposed vocal adaptors have various functions of, for example, so-called vocal conversion in which a vocal sound of a male is converted into that of a female or vice versa, and impartation of a so-called harmony effect in which a harmony sound constituting a consonance with respect to a vocal sound is imparted to the vocal sound. Although a vocal sound on which the former function or the vocal conversion is conducted is obtained as a result of complex processes, it is a so-called dry voice (voice having reverberation components that are relatively small) and is not different from a conventional vocal sound of a male or a female. Therefore even when a vocal sound on which the vocal conversion is conducted by a vocal adaptor is supplied to a karaoke amplifier and an echo or reverb is imparted to the vocal sound by the karaoke amplifier to be output, no difficulty occurs. By contrast, when a vocal sound to which a harmony effect is imparted by the vocal adaptor is supplied to the karaoke amplifier and an echo or reverb is imparted to the vocal sound by the karaoke amplifier, there arises a problem in that the resulting voice signal is reproduced as an obscure sound. This problem arises not only in the case where a harmony effect is imparted to a vocal sound but also in the case where a so-called wet voice (voice having reverberation components that are relatively large) generated by the vocal adaptor is supplied to the karaoke amplifier.